1. Field of the Invention
The invention is related to the field of communication systems, and in particular, to communication devices and methods of operating communication devices that provide enhanced services to users.
2. Statement of the Problem
Almost every house, apartment, condo, etc. is wired for phone service, commonly called POTS service. On a daily basis, people use the POTS service to place calls for business and personal use. The wiring for POTS service is typically a twisted-pair copper wire that connects the home to a central office of the local telephone company. The connection between the central office and the home over the twisted-pair wire is sometimes referred to as the “last mile”. For POTS service, a phone takes acoustic signals and converts them into analog signals that are the electrical equivalent of the acoustic signals in terms of volume and pitch. The phone then transmits analog signals to the central office.
The central office applies a low voltage to the twisted-pair wire using a power supply or battery. The voltage on the wire provides power to phones in the home. Because the central office provides power to the twisted-pair wire, phones in the home work even if the commercial electric power goes out in the home.
Recently, Internet access and email have become a daily routine. Many people access the Internet and their email accounts from a home computer using POTS service. Because the central office expects an analog signal, the home computer uses a modem to modulate digital data from the computer into analog signals. The modem then transmits the analog signals over the twisted-pair wire to the central office.
The analog transmission between the home computer and the central office only uses a portion of the twisted-pair wire potential bandwidth for transmission, which limits the bandwidth available to the home computer. Also, if the central office receives digital data destined for the home computer, the central office has to convert the digital data to analog signals and transmit the analog signals over the twisted-pair wire. The modem of the home computer then converts the analog signals back to the digital data. The conversion back and forth between digital and analog may limit the available bandwidth to about 56 Kbps. Consequently, the POTS service may not provide a desired bandwidth for accessing the Internet, sending emails, or other applications.
To receive higher bandwidths over the existing twisted-pair wire, communication providers have implemented services such as Digital Subscriber Line (DSL) service. DSL service provides voice service and data service simultaneously over the twisted-pair wire. Depending on the distance and twisted-pair circuit quality, a user subscribing to the DSL service can advantageously receive a bandwidth around 1.544 Gbits/s for accessing the Internet while still retaining traditional POTS service.
For DSL service, a DSL modem transmits digital signals at a high frequency over the twisted-pair wire simultaneously as analog signals travel over the twisted-pair wire at a low frequency. The analog signals comprise traditional POTS service generally used for voice calls. The digital signals are generally used for data services, such as accessing the Internet or sending email, but may also be used for voice calls, such as Voice over Internet Protocol (VoIP) calls. For the data services, a computer connects to an Internet Service Provider (ISP) through the DSL modem. Once connected to the ISP, the computer may receive digital signals directly from the ISP. The computer can receive the digital signals at a higher bandwidth than if the central office had to convert the digital signals to an analog signal.
Unlike the POTS service, the central office does not provide power to the DSL modem or the computer. The computer needs an independent power supply to operate. If the power is interrupted to the computer, the computer is not able to operate.
Another way to receive higher bandwidths is to subscribe to cable service. Cable service utilizes a coaxial cable for the cable service for high bandwidth data services. The user maintains POTS service separately over the twisted-pair wire. With cable service, the user can simultaneously use the POTS service for voice calls and use the cable service for accessing the Internet or sending email.
Although current computers can receive DSL service to make calls and surf the Internet, the features provided to the user for communications is limited. The voice features offered to the user are limited to the features normally provided by the POTS service (and the phone company). The features include voice mail, call waiting, and caller ID. The data services provided by DSL service are not currently used to add features to the POTS service. The POTS service (voice service) is typically used for phones and the DSL service (data service) is typically used for Internet and email. The POTS service is not used to enhance the data service and the data service is not used to enhance POTS service. Therefore, the features available to a user are limited, and a user may desire other features that are not currently available.
Also, computers set up for DSL service require power to operate. If the power is interrupted to the computer, then the computer can no longer communicate voice or data. This may be unfortunate in the event of brown outs, power surges, terrorist acts, storms, etc.